PUBLICATION
Structural and functional study of D-glucuronyl C5-epimerase
- Authors
- Qin, Y., Ke, J., Gu, X., Fang, J., Wang, W., Cong, Q., Li, J., Tan, J., Brunzelle, J.S., Zhang, C., Jiang, Y., Melcher, K., Li, J.P., Xu, H.E., Ding, K.
- ID
- ZDB-PUB-170214-229
- Date
- 2015
- Source
- The Journal of biological chemistry 290: 4620-30 (Journal)
- Registered Authors
- Li, Jie
- Keywords
- Crystal Structure, Enzyme Mechanism, Epimerization, Glce, Glycosaminoglycan, Heparan Sulfate, Heparin, d-Glucuronyl C5 Epimerase
- MeSH Terms
-
- Animals
- Carbohydrate Epimerases/chemistry*
- Carbohydrate Epimerases/genetics
- Carbohydrate Epimerases/metabolism
- Crystallography, X-Ray
- Heparitin Sulfate/chemistry
- Heparitin Sulfate/genetics
- Heparitin Sulfate/metabolism
- Protein Multimerization
- Protein Structure, Quaternary
- Protein Structure, Secondary
- Zebrafish*
- Zebrafish Proteins/chemistry*
- Zebrafish Proteins/genetics
- Zebrafish Proteins/metabolism
- PubMed
- 25568314 Full text @ J. Biol. Chem.
Citation
Qin, Y., Ke, J., Gu, X., Fang, J., Wang, W., Cong, Q., Li, J., Tan, J., Brunzelle, J.S., Zhang, C., Jiang, Y., Melcher, K., Li, J.P., Xu, H.E., Ding, K. (2015) Structural and functional study of D-glucuronyl C5-epimerase. The Journal of biological chemistry. 290:4620-30.
Abstract
Heparan sulfate (HS) is a glycosaminoglycan present on the cell surface and in the extracellular matrix, which interacts with diverse signal molecules and is essential for many physiological processes including embryonic development, cell growth, inflammation, and blood coagulation. D-glucuronyl C5-epimerase (Glce) is a crucial enzyme in HS synthesis, converting D-glucuronic acid to L-iduronic acid to increase HS flexibility. This modification of HS is important for protein ligand recognition. We have determined the crystal structures of Glce in apo-form (unliganded) and in complex with heparin hexasaccharide (product of Glce following O-sulfation), both in a stable dimer conformation. A Glce dimer contains two catalytic sites, each at a positively charged cleft in C-terminal α-helical domains binding one negatively charged hexasaccharide. Based on the structural and mutagenesis studies, three tyrosine residues, Tyr(468), Tyr(528), and Tyr(546), in the active site were found to be crucial for the enzymatic activity. The complex structure also reveals the mechanism of product inhibition (i.e. 2-O- and 6-O-sulfation of HS keeps the C5 carbon of L-iduronic acid away from the active-site tyrosine residues). Our structural and functional data advance understanding of the key modification in HS biosynthesis.
Genes / Markers
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Orthology
Engineered Foreign Genes
Mapping